DiskFileItemFactory.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.t2framework.confeito.apache.commons.fileupload.disk;

import java.io.File;

import org.t2framework.confeito.apache.commons.fileupload.FileItem;
import org.t2framework.confeito.apache.commons.fileupload.FileItemFactory;
import org.t2framework.confeito.apache.commons.io.FileCleaningTracker;

/**
 * <p>
 * The default
 * {@link org.t2framework.confeito.apache.commons.fileupload.FileItemFactory}
 * implementation. This implementation creates
 * {@link org.t2framework.confeito.apache.commons.fileupload.FileItem} instances
 * which keep their content either in memory, for smaller items, or in a
 * temporary file on disk, for larger items. The size threshold, above which
 * content will be stored on disk, is configurable, as is the directory in which
 * temporary files will be created.
 * </p>
 * 
 * <p>
 * If not otherwise configured, the default configuration values are as follows:
 * <ul>
 * <li>Size threshold is 10KB.</li>
 * <li>Repository is the system default temp directory, as returned by
 * <code>System.getProperty("java.io.tmpdir")</code>.</li>
 * </ul>
 * </p>
 * 
 * <p>
 * When using the <code>DiskFileItemFactory</code>, then you should consider the
 * following: Temporary files are automatically deleted as soon as they are no
 * longer needed. (More precisely, when the corresponding instance of
 * {@link java.io.File} is garbage collected.) Cleaning up those files is done
 * by an instance of {@link FileCleaningTracker}, and an associated thread. In a
 * complex environment, for example in a web application, you should consider
 * terminating this thread, for example, when your web application ends. See the
 * section on "Resource cleanup" in the users guide of commons-fileupload.
 * </p>
 * 
 * @author <a href="mailto:martinc@apache.org">Martin Cooper</a>
 * 
 * @since FileUpload 1.1
 * 
 * @version $Id: DiskFileItemFactory.java 607869 2008-01-01 16:42:17Z jochen $
 */
public class DiskFileItemFactory implements FileItemFactory {

	// ----------------------------------------------------- Manifest constants

	/**
	 * The default threshold above which uploads will be stored on disk.
	 */
	public static final int DEFAULT_SIZE_THRESHOLD = 10240;

	// ----------------------------------------------------- Instance Variables

	/**
	 * The directory in which uploaded files will be stored, if stored on disk.
	 */
	private File repository;

	/**
	 * The threshold above which uploads will be stored on disk.
	 */
	private int sizeThreshold = DEFAULT_SIZE_THRESHOLD;

	/**
	 * <p>
	 * The instance of {@link FileCleaningTracker}, which is responsible for
	 * deleting temporary files.
	 * </p>
	 * <p>
	 * May be null, if tracking files is not required.
	 * </p>
	 */
	private FileCleaningTracker fileCleaningTracker;

	// ----------------------------------------------------------- Constructors

	/**
	 * Constructs an unconfigured instance of this class. The resulting factory
	 * may be configured by calling the appropriate setter methods.
	 */
	public DiskFileItemFactory() {
		this(DEFAULT_SIZE_THRESHOLD, null);
	}

	/**
	 * Constructs a preconfigured instance of this class.
	 * 
	 * @param sizeThreshold
	 *            The threshold, in bytes, below which items will be retained in
	 *            memory and above which they will be stored as a file.
	 * @param repository
	 *            The data repository, which is the directory in which files
	 *            will be created, should the item size exceed the threshold.
	 */
	public DiskFileItemFactory(int sizeThreshold, File repository) {
		this.sizeThreshold = sizeThreshold;
		this.repository = repository;
	}

	// ------------------------------------------------------------- Properties

	/**
	 * Returns the directory used to temporarily store files that are larger
	 * than the configured size threshold.
	 * 
	 * @return The directory in which temporary files will be located.
	 * 
	 * @see #setRepository(java.io.File)
	 * 
	 */
	public File getRepository() {
		return repository;
	}

	/**
	 * Sets the directory used to temporarily store files that are larger than
	 * the configured size threshold.
	 * 
	 * @param repository
	 *            The directory in which temporary files will be located.
	 * 
	 * @see #getRepository()
	 * 
	 */
	public void setRepository(File repository) {
		this.repository = repository;
	}

	/**
	 * Returns the size threshold beyond which files are written directly to
	 * disk. The default value is 10240 bytes.
	 * 
	 * @return The size threshold, in bytes.
	 * 
	 * @see #setSizeThreshold(int)
	 */
	public int getSizeThreshold() {
		return sizeThreshold;
	}

	/**
	 * Sets the size threshold beyond which files are written directly to disk.
	 * 
	 * @param sizeThreshold
	 *            The size threshold, in bytes.
	 * 
	 * @see #getSizeThreshold()
	 * 
	 */
	public void setSizeThreshold(int sizeThreshold) {
		this.sizeThreshold = sizeThreshold;
	}

	// --------------------------------------------------------- Public Methods

	/**
	 * Create a new
	 * {@link org.t2framework.confeito.apache.commons.fileupload.disk.DiskFileItem}
	 * instance from the supplied parameters and the local factory
	 * configuration.
	 * 
	 * @param fieldName
	 *            The name of the form field.
	 * @param contentType
	 *            The content type of the form field.
	 * @param isFormField
	 *            <code>true</code> if this is a plain form field;
	 *            <code>false</code> otherwise.
	 * @param fileName
	 *            The name of the uploaded file, if any, as supplied by the
	 *            browser or other client.
	 * 
	 * @return The newly created file item.
	 */
	public FileItem createItem(String fieldName, String contentType,
			boolean isFormField, String fileName) {
		DiskFileItem result = new DiskFileItem(fieldName, contentType,
				isFormField, fileName, sizeThreshold, repository);
		FileCleaningTracker tracker = getFileCleaningTracker();
		if (tracker != null) {
			tracker.track(result.getTempFile(), this);
		}
		return result;
	}

	/**
	 * Returns the tracker, which is responsible for deleting temporary files.
	 * 
	 * @return An instance of {@link FileCleaningTracker}, defaults to
	 *         {@link org.apache.commons.io.FileCleaner#getInstance()}. Null, if
	 *         temporary files aren't tracked.
	 */
	public FileCleaningTracker getFileCleaningTracker() {
		return fileCleaningTracker;
	}

	/**
	 * Returns the tracker, which is responsible for deleting temporary files.
	 * 
	 * @param pTracker
	 *            An instance of {@link FileCleaningTracker}, which will from
	 *            now on track the created files. May be null to disable
	 *            tracking.
	 */
	public void setFileCleaningTracker(FileCleaningTracker pTracker) {
		fileCleaningTracker = pTracker;
	}
}